1. Field of the Invention
The present invention concerns clutch release bearings suitable for automotive vehicles.
2. Description of the Prior Art
A clutch release bearing comprises an actuator device, in practice a fork, hereinafter referred to as an actuator fork, acting on an operating member, and a drive element, mounted rotatable with respect to said operating member, and which, under the action of said operating member, acts on the release device of a clutch.
In practice, to act on the operating member of such a clutch release bearing, the associated actuator fork has two arms, and said operating member includes, for said arms of said actuator fork, two axial flats providing axial guidance, in diametrically opposite positions, and two transverse flats providing axial support, also in diametrically opposite positions, and usually, but not necessarily, at right angles to the axial guide surfaces.
This application concerns more particularly a pull type clutch release bearing, that is to say a clutch release bearing exerting a tractive force on the release device of the clutch in question, wherein its drive element is engaged behind said clutch release device.
In this type of clutch release bearing, the transverse flats providing axial support for the actuator fork are usually formed respectively on two radial arms projecting radially from a sleeve on the operating member, and axially positioned with respect to the drive element, on the other side of the axial guide surfaces also provided on said sleeve for said actuator fork.
For reasons of symmetry, the axial guide flats extend on both sides of the axial plane of the assembly which is substantially perpendicular to them, and, most often, this plane, hereinafter referred to as the median axial plane of the assembly, passes through the median point of the radial arms.
One of the problems encountered when mounting such clutch release bearings results from the fact that the mounting procedure involves a relative engagement of the clutch release bearing and actuator fork, the fork arms having to be engaged transversely between the radial arms which the operating member of the clutch release bearing possesses for its action, and the running part of said operating member.
In other words, the fork arms must be engaged behind the radial arms of the clutch release bearing.
In a pull type clutch release bearing, said clutch release bearing is supported by a clutch, its drive element being engaged behind the clutch release device, whereas the actuator fork is usually independently supported by the housing of a gearbox, being mounted at a median articulation point to pivot about a transverse spindle or a fixed ball joint.
It is therefore necessary, on the increasing relative axial proximity of said gearbox housing and said clutch, usually supported by the housing of the corresponding engine, to engage progressively the fork arms behind the radial arms of the clutch release bearing.
This operation, involving presenting the actuator fork initially substantially flatwise, in the horizontal plane, and, by fitting, gradually moving said actuator fork to the vertical, as said fork arms engage behind said radial arms of said clutch release bearing, is difficult to do, more particularly when said actuator fork is mounted pivoting about a ball joint, because of the additional degree of freedom of movement of said ball joint.
Moreover, it may prove impossible, since the pivoting movement of the actuator fork required to move from the horizontal to the vertical plane requires a substantial space, which is not always available.
The objective of the present invention is to provide an arrangement which, taking advantage of the fact that the operating member of a clutch release bearing is mounted rotatable with respect to the drive element with which it is associated, enables these difficulties to be surmounted and facilitates in all cases the assembly of a pull type clutch release bearing.